If you're looking to get some real personality out of your engine, swapping those factory 5.7 hemi cams for something with a bit more bite is usually the first big step. Let's be honest, the 5.7 Hemi is a workhorse, but from the factory, it's a little bit choked up. Chrysler tuned these things for quiet commutes and decent gas mileage, which is fine for some people, but if you're reading this, you probably want that signature idle "chop" and the kind of passing power that actually puts you back in your seat.
Choosing a cam isn't just about picking the one with the biggest numbers on the box, though. There's a lot to consider, from whether you've got a VVT engine to how much you're willing to spend on supporting parts like torque converters and valve springs.
Understanding the VVT vs. Non-VVT Divide
Before you even start looking at specific 5.7 hemi cams, you have to know what year your engine was made. This is the biggest "gotcha" in the Hemi world. If your truck or car is from 2003 to 2008, you've got the non-VVT (Variable Valve Timing) version. These are a bit simpler to work on, but they don't have the same head flow as the later models.
If you're rocking a 2009 or newer model, you've got what people call the "Eagle" engine. These come with VVT, and while it adds a layer of complexity to the cam swap, the performance ceiling is much higher. The Eagle heads flow incredibly well right out of the box. However, when you swap cams in a VVT engine, you usually need a "phaser limiter." This little piece of hardware prevents the cam from advancing or retarding too far and smashing your valves into your pistons—which, as you can imagine, is a very bad day.
The Infamous MDS Delete
You can't really talk about 5.7 hemi cams without mentioning the Multi-Displacement System (MDS). That's the tech that shuts down four cylinders to save gas. While it sounds good on paper, it's the primary reason for the "Hemi Tick" and lifter failure. Most performance cams are not compatible with MDS lifters.
If you're going through the trouble of pulling the intake and the heads to swap a cam, you'd be crazy not to do an MDS delete. This means swapping in non-MDS lifters and plugging the oil holes. It makes the engine way more reliable and allows you to run a much more aggressive cam profile. Plus, nobody wants their V8 to sound like a weird V4 when they're cruising down the highway anyway.
Picking Your "Stage"
Most companies categorize their 5.7 hemi cams by "Stages." It's a bit of a marketing term, but it helps give you an idea of what to expect.
Stage 1: The "Daily Driver" Cam
A Stage 1 cam is perfect if you want a nice bump in power—usually around 30 to 40 horsepower—without ruining the way the car drives. You can usually run these with the stock torque converter, and the idle is smooth enough that your spouse won't complain about the car shaking at stoplights. It's the "stealth" option.
Stage 2: The Sweet Spot
This is where most people end up. A Stage 2 cam offers a noticeable "lope" at idle. It sounds like a muscle car should. You'll see bigger gains in the mid-to-high RPM range, but there's a catch: you'll almost certainly need an aftermarket torque converter with a higher stall speed. If you try to run a Stage 2 cam on a stock converter, the car might feel sluggish off the line or try to "push" through the brakes at red lights.
Stage 3 and Beyond: The Rowdy Builds
Stage 3 5.7 hemi cams are for the guys who don't mind a little bit of a headache in exchange for maximum power. The idle is aggressive, the power comes on late, and you'll need a lot of supporting mods. We're talking long-tube headers, a high-stall converter (3000+ RPM), and maybe even some gear changes in the rear end to keep the engine in its power band.
Supporting Mods You Can't Ignore
I've seen too many people buy a cam and think they're done spending money. That's rarely the case. When you increase the lift and duration with new 5.7 hemi cams, the factory valve springs usually aren't up to the task. They can "coil bind" or simply not have enough tension to close the valve fast enough at high RPMs. Upgrading to high-performance beehive springs is pretty much mandatory.
Pushrods are another big one. The factory Hemi pushrods are okay for stock loads, but they can flex under the pressure of a performance camshaft. Chromoly pushrods are a cheap insurance policy to keep your valvetrain stable.
And then there's the oil pump. Since you've already got the front of the engine torn apart, many guys swap in a high-volume oil pump—often the one from the 6.4L SRT engine. It's a direct fit and provides better lubrication, which these engines desperately need.
The Importance of Tuning
You can have the best 5.7 hemi cams in the world, but if your computer doesn't know what to do with them, your car will run like garbage. Modern Hemis are incredibly sensitive to airflow changes. Once you swap the cam, the engine is going to be pulling in way more air than the factory fuel maps are prepared for.
You'll need a handheld tuner (like a DiabloSport) and, more importantly, a custom "email tune" or a session on a chassis dyno. A good tuner will adjust the fuel trims, spark timing, and idle speed to make sure the car is safe to drive and making the most power possible. Without a tune, you'll likely deal with stalling, surging, and a permanent check engine light.
What Does it Actually Feel Like?
So, after you've spent the weekend covered in oil and coolant, what's the payoff? The first thing you'll notice is the sound. There is nothing quite like the sound of 5.7 hemi cams hitting that rhythmic chop through a set of decent mufflers. It changes the entire vibe of the vehicle.
On the road, the truck or car will feel more "alive." The 5.7 usually falls flat on its face after about 5,000 RPM. With a good cam, it'll keep pulling hard all the way to the redline. It transforms the engine from a low-end torque monster into a broad-power-band beast. You might lose a tiny bit of bottom-end grunt if you go too big, but the trade-off in the mid-range and top-end is usually more than worth it.
Is it Worth Doing Yourself?
If you're handy with a wrench and have a garage, a cam swap is doable. But it's not a beginner job. You have to be comfortable pulling the radiator, the harmonic balancer, and the entire front timing cover. On the VVT engines, getting the timing marks lined up perfectly is critical. If you're off by even one tooth, you're looking at potential engine damage.
If you're paying a shop to do it, expect to pay a decent chunk in labor. It's a time-consuming process. However, considering it's one of the few mods that can add 50+ horsepower to a naturally aspirated 5.7, it's often considered the best "bang for your buck" after you've already done the basic intake and exhaust.
At the end of the day, picking out 5.7 hemi cams is about knowing your goals. If you want a reliable daily that sounds cool, go Stage 1 or a mild Stage 2. If you're building a weekend track toy, go big and don't look back. Just make sure you do the lifters and the springs while you're in there—your engine will thank you later.